Somali pirates fired on a French navy vessel early today after apparently mistaking it for a commercial boat, the French military said. The French ship gave chase and captured five suspected pirates. La Somme, a 3,800-ton refuelling ship, "was probably taken for a commercial ship by the two small skiffs" some 250 nautical miles off Somalia, said Rear Admiral Christophe Prazuck, adding: "They understood their mistake too late." One skiff fled, but La Somme caught the other after an hour-long chase. "There were five suspected pirates on board. No arms, no water, no food," Prazuck said.